Means and method for converting speech into visible indicia



W. W. J. FULLER Nov. 22, 1938.

MEANS AND METHOD FOR CONVERTING SPEECH INTO VISIBLE INDICIA Filed Nov.18, 1935 3 Sheets-Sheet 1 Nov. 22, 1938. w, w, J FULLER 2,137,888

MEANS AND METHOD FOR CONVERTING SPEECH INTO VISIBLE INDICIA Filed Nov.18, 1955 3 Sheets-Sheet 2 I I l I l l l l l l I l l I a I I l e l l I Il l l i J Nov. 22, 1938. v w. w. J. FULLER 2,137,333

mmns AND usmon FOR convnmma SPEECH INTO VISIBLE mmcn Filed NOV. 18, 19353 Sheets-Sheet '3 w 7 j mug 3 E T as I'm-ml Patented Nov. 22, 1938UNITED STATES PATENT OFFICE 8.181.888 J mus AND METHOD I! CONVERTINGSPEECH INTO wanna INDIQA This invention relates to a method and meansfor analysing the wave terms of spoken sounds andfor causing thosespoken sounds to make a visible indication. The latter may be in the siorm of an illuminated letter. symbol, or word sign, or on the otherhand may be in the term of a permanent printed record.

It is a well known fact that speech is a complex phenomenon oi pitch orfrequency diilerences: volume, intensity or amplitude difi'erences: and

quality or number and relative strength 01' partials or harmonics orwave form diilerences. In the sense of hearing, all three of thesecomponents, and the duration or time element of each, are utilized forarticulation or intelligibility.

It is an object of the present invention to provide a method andapparatus for converting intelligible sounds (primarily speech sounds)into intelligible visible indicia and, in accordance with thisinvention, I take into account all 0! the above mentioned factors,whereas, in the prior art, as far as I am aware, only the matter ofirequency ditlerences has been considered. For this reason, no operativemethod oi, or apparatus for converting speech sounds into intelligiblevisible indicia have been produced, prior to my invention.

It is the primary object of the present invention, therefore, to providea method and means for converting sounds into intelligible visible tom,

such as word signs, letters or characters, either exhibited, illuminatedor printed.

It is an object of the invention to provide a method and apparatus whichwill make possible the conversion oi speech sound into visible form,

' for instance, to enable totally dear persons to understand, visually.the spoken word. The invention, 0! course, is not confined to use by thedeal, as it is oi utility in converting speech into a permanent printedrecord.

According to the pinciple of this invention,

speech sounds orthe like are first converted into a correspondingpulsating current, for instance.

by the use oi a microphone, a series of filters. and an audio-frequencyamplifier. This current, and an appropriate sweep circuit, control theelectron beam to trace a path corresponding to the spoken sound. As iswell understood, either electro-magnetic or electro-static means, thatis, coils or plates, respectively, or a combination of both may be usedto control deflection. 'flle voice current circuit may be connected toone pair 0! electron beam defiecting plates or coils oi the cathode raytube, and the other pair oi plates or coils associated therewith may beconnected either to a signal synchronised sweepcirouit,ortoaslgnalreleased.singlestroke sweep circuit, as protested.

Instead oi using a conventional cathode ray tube, in which the electronbeam is projected directly onto a fluorescent screen, merely for s thepurpose oi illuminating the same, a special type 0! target is providedin my invention. The target is associated with the cathode ray tube, inthe path 01' the, electron beam, and comprises essentially a maskprovided with apertures of i0 novel type, as explained below, and meansbehind the mask adapted to be ailected by the beam projecting throughone or more oi the apertures.

The mask is provided with apertm'es positioned thereon in accordancewith a plurality of lo diilerent patterns, each pattern corresponding tothe wave form or path traced thereon by the electron beam when actuatedor controlled by a particular previously recorded sound. Eachsoundadaptedtobeindicatedvisuallybytheao method and apparatus or thepresent invention will,oicourse,causetheelectronbeamtotrace a diilerentwave form on the mask. These curves maybetracedbeiorehandbytheuseoi oilcovered photographic plate or by the discoloring oi as the metal of themask by the electron beam. One or more apertures may then be drilled orotherwise i'ormed at convenient points along each curve, care beingtaken to avoid forming the apertures where the diilerent sound tracescross to one another, and to avoid too close a spacing of the apertures.For each sound trace, a diilerent position, number, size, or shapeofapertures are provided.

Whenthe eleotronbeamisactuatedandconas trolled by a predetermined sound,it will necessarily travel along the path previously recordedcnthemaskbyacorrespondingscundandwill be projected through the. apertureor apertures positioned on that path, but through no other 40 apertures.

Since, as stated, theposition, number, size or shape oi theapertures-are difierent, the eilectoithebeamproiectedtherethroughwlllbeditterentioreachsoundanditisanimportantfeature of the present invention to provide means, which may be 0!several. diilerent types, forutilisingtheproiectedandscreenedbeamtoselect and actuate an apropriatevisual indicator.

Three alternative ways are described below for so utilising the enersyoi the electronbeam passing through the screen to select and actuate anindicator. The first, i'or convenience, may be termed the impulsesystem", the second, the "charge accumulative system. and the third, these ect fluorescent or direct illumination systern".

In the first two systems, I position behind the screen a chargeaccumulating or conducting device, preferably, but not necessarily, inthe form of a Faraday cage. In the third, I position behind the mask afluorescent screen, preferably provided with visible lndicia, such, forinstance, as stenciled letters or word signs. For each system, aslightly different form of target mask is used, although all three arebas-' ically the same. In the impulse system, each wave form or path isprovided with a plurality of apertures which differ, from pattern topattern as to their shape, spacing and/or number. In the accumulativecharge system the apertures along each sound trace diiier as regardstheir number or size, whereas in the third (direct illumination) system,only one aperture is provided for each sound trace, and the aperturesdiffer from one another only in the matter of their Position.

In the first or impulse system, individual pulses are applied to theconductor positioned there behind as the electron beam travels over theapertures in the mask arranged on a particular wave form pattern. Thesepulses are amplified. and may be used to actuate a high speed electricalintegrator or indicator for actuating printing keys. Thus, each pathtraversed by the electron beam will create, in the circuit connected tothe target, a series of unidirectional pulses which are different fromseries to series in the matter of their number, duration, or periodicfrequency or a combination thereof. Indicators adapted to be controlledand actuated by such pulsating currents are known in the art.

In the case of the cumulative charge system, the individual pulsesimparted by the electron beam to the charge accumulator behind the mask,as a result of the passage of the beam through the several openings on aparticular path, are stored 1m until the end of the sweep of the beamfor that particular sound. At the end of the sweep, a circuit is closedfrom the target to ground, and the potential of the discharge, whichwill be diiferent for each sound track pattern, is utilized to controlthe selection of the appropriate indicator.

In the direct illumination system, the beam will pass through only oneaperture during its traverse of a particular sound track. Positionedbehind the mask is a fluorescent screen. adapted to be illuminated bythe electron beam when it passes through the mask. Since the spot ofillumination will be different for each sound trace, the mask acts as aselector. At the points on the screen, or on the end of the tube,corresponding to the spots which will be illuminated by the beam,appropriate indicia, such as letters or other characters are positioned,so that they will be illuminated or indicated by the luminous spots onthe fluorescent surface. Consequently, a letter or other charactercorresponding to the spoken sound will be illuminated by the electronbeam.

Thus, the spoken sound automatically controls the actuation of aparticular indicating means, so that a visual indication correspondingto it is made.

As stated above, when either of the first two ways is used, there ispositioned behind the mask a charge receiving device which may be in thenature of a Faraday cage. Such a device is particularly desirable in thecharge accumulative system, because means must be provided to receivethe successive charges projected through the screen. The same device maybe used in the impulse system, or a simple plate of material of highelectron absorption coefficient may be substituted. The mask should beinsulated from the conducting or accumulating member, and thisinsulation is accomplished by Spacing the members apart and, if desired,connecting the mask to ground. The apertures in the mask should havewell defined, sharp edges.

Ii a Faraday cage type of collector is associated with the mask, itsfront face preferably is provided'with openings registering with thepattern openings in the screen so that electrons projecting through theopenings can enter the cage to be absorbed by the walls thereof, but sothat the electrons will be restrained from being reflected outwardlythereof.

In practicing my invention, it is essential that all of the sound wavestraced on the target start from the same point and that all are releasedor set in operation by the voice itself. Each sound wave or trace willbe different from the others. and the apertures are so located on thedifIerent traces as to take advantage of these differences mosteillciently.

When the impulse system is used, the charge absorbing and conductingelement behind the screen may be connected through appropriateamplification to a counter or indicator of the type used in teletypework or any other type of indicator, adapted to be actuated by thenumber, frequency and/or duration of the successive pulses may be used.The charge absdrbing and conducting member behind the screen in theimpulse system is so connected that the impulses are registered on theindicator circuit immediately as the electron beam traverses the patternand projects through the openings thereon.

In the case of the charge accumulating method, the charges resultingfrom the projection of the beam through the several openings are storedup during the entire time that the beam travels across the mask, andmeans must be provided for discharging this accumulated charge at theend of the travel of the beam, so that the current may be utilized toeffect the necessary selection of the proper indicating means. Thismeans may comprise an auxiliary electrode positioned at the end of theseveral traces. adapted to close a circuit, by an appropriate relay, sothat the accumulated current will flow from the collector to ground. Bythe interposition of an appropriate resistor in the last mentionedcircuit, the potential drop across it will be applied to an appropriateamplification circuit to control the indicators. Alternatively, I mayuse a relay tube interposed in the beam sweep circuit to close thecircuit from the collector to ground when the current has risensumciently high in the sweep circuit to have moved the beam all the wayacross the target.

with my invention, either of two circuits. termed "sweep circuits" maybe used to con trol the movement of the beam across the target. Theflrst may be described as a voice released sweep circuit, which consistsof a circuit adapted to cause the beam to make a single, relatively slowstroke across the target for each sound. The second is a voicesynchronized sweep circuit, which is recurrent, i. e., similar to theso-called sawtooth relaxation oscillation impulses. In this type, thebeam makes a great ans-aces plurality of strokes across the targetduring each sound. In the former, a constant period of time is consumedby the beam during each traverse of the target. In the latter. the sweepvelocity bears a definite sub-multiple relationship to the voicefrequencies.

The voice stroke, signal released sweep circuit is preferable in certaincases, but it. must be understood that my invention is not limitedthereto. A control electrode is located at the beginning position ofrest to which the beam is normally directed when no voice current is inthe sound circuit. When a current is impressed upon this circuit, by theadmission of a sound, the beam will be deflected by the detector platesor coils in the cathode ray tube and will then be removed from thecontrol electrode. Such removal of the beam will make a change in thecurrent in a circuit connected to that electrode, which, through anappropriate thermionic relay, will start the operation oi the sweepcircuit to move the beam across the target. An electronic time delay maybe inserted in this circuit, e. g., a current limiting tube, that is,one which draws a constant plate current may be used to decrease orcontrol the sweep velocity if desired.

As is well known in the art, appropriate weak couplings between theimpressed voice currents and the time base circuit may be used for"looking or maintaining a relationship between the voice current and therate of sweep or time of horizontal traverse.

In the foregoing general description, mention has been made of the useof a single electron beam tube in connection with this invention, but,for certain purposes, it is often desirable to use two or more suchtubes connected in parallel. If it is desired to make the apparatuscapable of indicating a great plurality of difiering sounds, it is ofadvantage to use a plurality of electron tubes, each of which isprovided with a screen having the openings thereof arranged on differentpatterns so that each tube controls a different group of visualindicators and is adapted to be actuated by a correspondingly differentgroup of sounds. In such a case, the beam of electrons in each tube maymove simultaneously along the same wave form, for each sound, but themask in only one tube will have openings corresponding to each waveform, and that tube alone will be operative to control an indicator.

Alternatively, the tubes connected in parallel may be arranged in such acircuit that they operate in sequence so that one tube will operate atthe beginning of a rather long sound, another tube at the middle portionthereof, and if desired, a third tube at the end of the sound. Each tubehas associated with it a screen having a plurality of patternscorresponding to sound waves of the type that will be traced thereon asa result of the particular sounds which will control the beams. Thus,the apparatus in accordance with this conception. will be capable oftaking care of long and involved sounds.

Although the accumulative charge system described generally above hascertain desirable features, it is inherently limited in the number ofwave forms that can be analyzed, by reason of the fact that the amountof the charge that can be stored up in the charge accumulator isdefinitely limited by the nature and size thereof, and by the fact thatthe selection is based simply on magnitude of charge. With the impulsesystem, the charge absorbing and conducting member imposes no suchlimitation, because an almost infinite number of variations in thenumber, frequency, and duration of impulses can be worked out. As statedabove. may electrical cir cults and systems for receiving anddiscriminating between electrical impulses are known in the art, and thesystem described below is illustrative only. Because of the shortness ofthe pulses and of the intervals between the pulses, it is preferablethat the electric circuit be of a nature as to permit the functioning ofthe counter or indicator and/or to compensate for the time (actor of theprinting mechanism used. The circuit retains, delays or spreads out thepulses until such time as the printer is clear and releases them at arate which mechanical keys can follow. I prefer to use a gas vaporelectron tube, of the thyratron type. It is essential to prevent theinterpreting impulses from outstripping or getting ahead of the timelimitations of the particular high speed counter or printing mechanismadapted to be controlled thereby.

In the accompanying drawings, I have shown diagramatically a number ofdifierent methods and means for accomplishing the obiects of thisinvention. It must be understood that the drawings are illustrativeonly, and are not restrictive of the invention.

In the drawings:-

Figure 1 is a diagrammatic view of one form of the invention;

Figure 2 is a diagrammatic view of a modification;

Figure 3 is an enlarged detail at one end of the cathode ray tube ofFigure 2;

Figure 4 is an end elevation of the device of Figure 3;

' Figure 5 is an enlarged detail of a cathode ray tube which may be usedin connection with the method and apparatus of Figure 1;

Figure 6 is a circuit diagram of one form of the invention;

Figure 7 is a modified circuit which may be used with the circuit ofFigure 6;

Figure 8 is a diagrammatic elevational view of an apertured mask whichmay be used with the cathode ray tube;

Figure 9 is a circuit diagram of a modificatron, in which two cathoderay tubes are connected in parallel; and

Figure 10 is a diagrammatic view of a novel printing mechanism.

Figure 1 shows one plan of arrangement of the various elements of theinvention. A telephone transmitter or microphone l is connected tosuitable amplification 2, and thence to a filter or series of filters 3.A sweepcircuit l is interposed between the filter and the electron beamtube 6. The cathode ray device may be provided with a metallic envelope,and includes horizontal plates 6 and vertical plates 1 which causedeflection of the cathode ray beam in two directions. Thus, the beamwill trace a wave form path across an apertured mask 8. Positionedbehind the mask is a collector or conductor 9, which, for instance,- maybe a Faraday cage. This is connected, through appropriate amplificationIll, to an indicator or printer II.

In the circuit from the filter 3 to the horizontal plates 6, I mayprovide, it desired. an amplitude control device I! for the currents inthat circuit.

In the system of Figure 2, instead of using a charge collector with thecathode ray tube, I provide a fluorescent screen I 3 and a plurality ofvisual indicators i4, adapted to be illuminated to make a properindication. ls shown in I'llure 3. the inner surface of the end face ofthe tube may be provided with a coating of fiuorescent material is. suchas calcium or strontium tungstste. sine sulphate or the like.Ordinarily. such materials are poor conductors. and in order to increasethe excited time life of the material. it is desirable to compoundtherewith a good conductor to spread the fiuoreecence. Moreover. itlsdesirabletoaddatraceodieadtoincrease the sensitivity of the coating.

Onthesurfaceoftheendfaceofthetubel provide a plurality of visual indiciall, which maybeintheformof dark figuresonatransluccnt ground orstenciled openings in a relatively o aque coat. These figures may beilluminated directly by the fluorescent material positioned therebehind,or, small spots may be illuminated immediately above or below eachindicia.

ThescreenlassociatcdwiththetubeofFigures 2 and 3 is provided with aplurality oi aperturcs it, ll. etc.. each being adapted to illuminate adifi'erent indicia when the electron beam projects therethrough. Theapertures are positioned so that one aperture only lies on each waveform path adapted to be traversed by the beam. Thus, only one indiciawill be illuminated by each sound.

Referring to Figures ti and t, a screen adaptedtobeusedwiththesystemofFigurel isdisclosed. This screen has a pluralityof openings it, It, etc., l1, l1, spaced along the paths It, it, etc.,adapted to be traversed by the electron beam as controlled by differentsounds. As stated above. the number, sise, shape or spacing of theopenings along the paths are difierent. Consequently, the collector it.which may be in the form of a Faraday cage It. will be subjected todiflerent amounts, numbers, or frequencies oi electron charges for eachwave form path traversed by the beam. These charges or impulses areconducted from the collector by an appro- Driate circuit throughappropriate amplification to the indicator or printer ii.

Referring to Figure 6, the microphone or telephone transmitter i isshown as connected to a conventional resistance capacitance coupledtwostage amplifier 28. A three-stage filter chain a is shown connectedto the output of the ampliher but, of course. it must be understood thatthe filter chain could precede the amplification. The number of filterunits or elements shown in the chain is arbitrary, as any suitable ordesired.

number may be used. Although a particular class of filter is shown. itshould be \mderstood that high pass, low pass or band pass filters maybe substituted.

In circuit with the filters and the cathode ray tube. there is a sweepcircuit 4. which, as shown in Figure 6. is of the signal synchronised.recurrent stroke typ This circuit applies electrical charges to thevertically disposed plates to impart horizontal movement -to the beam,to cause the beam to sweep longitudinally of the screen. The voicecurrent is also applied to the other pair of plates 0 to control themovement of the beam in the opposite direction.

AsindicatedatllinFlguredacircuitis provided in which the impulses fromthe Faraday cage II are applied, successively to the grids of aplurality of vapor discharge electron tubes. An amplifier or any meansor device for accelerating the electron motion may be used between thecage and the first tube in the circuit 1!. Thetubesofthiscircuitarearrangedinamanner known as a ring circuit, andimpulses imparted theretoarestoredupinthetubessuccessively and areremoved therefrom successively by the final tube 2!. which also restoreseach tube successively to its former condition. These impulses, asdischarged from the tube it. serve to actuate a printing mechanism ofany desired type such, for instance. as shown in Figure 10. Anyequivalent circuit, adapted to perform the general function of retainingthe impulses. or of accommodating the inherent time delay of mechanicalprinting mechanism is suitable.

In the circuit of Figure 6. and interposed between the voice circuit andthe printing magnet II, there is an appropriate electronic time delayIt. This device is adjustable so that a printing impulse will be appliedto the printing magnet it through conductors It following apredetermined time after the initiation of current in the voice circuit.

Thus, the circuit II is a time delay to permit the individual impulsesto be recorded on the printing device. so that the inherent time factorof the mechanical printing device will be compensated for and eachimpulse will have its proper effect on the counter. The time circuit itcontrols the printing impulse, and delays that impulse sufllciently topermit the printer to have been moved to the proper position beforeprinting. If simple words are used, this control is superfiuous.

Instead of using a separate circuit for controlling the printingimpulse, that impulse m y betransmittedoverthesame circuitastheindicatorselecting impulses by the use of a voice synchronized motor. clutchdriven series of cams to distribute or direct the selection of a finalpath to the printing key of a particular sound.

In Figure I, an alternative sweep circuit II is shown. Such a circuit isa single stroke. s al released circuit. In connection with this type ofcircuit, one may use a control electrode I! (Figure 8), associated withthe mask I. when the electron beam is caused to move of! of the controlelectrode 21 at the position of rest by a current fiowing in the voicecircuit. the tube It (Figure '1) will permit the flow 0! current throughthe sweep circuit, and as this current gradually increases, the beammoves. relatively slowly. across the target. When a predeterminedpotential has been thus created in the sweep circuit, the beam will havetraveled all the way across the screen, and the relay 31 will close.'Ihereupon, a printing impulseotcurrentwillfiowthroushthe wires as tothe printing solenoid It associated with the indicator.Thevoicecurrentfiowsintotbiscircult through wires It, connected to thehorizontallydisposedplatesiotthe cathoderaytube. Instead of using therelay TI to initiate printingimpulseattheendottbetraverseoithe beamacross the target, an auxiliary control electrode 11' (Figure 8)maybeprovided,andinsuch a case, that electrode should be connectedthrough an appropriate time delay circuit, such as that shown at I inFigure 6 to the printing solenoid.

Figure 9 discloses a preferred manner in which twoormorecathoderaytubeslandl' maybe connected in parallel. In thisdiagrammatic i1- lustration, the signal input is represented at 40 andthe sweep input at I. The sweep circuits l2, 48, associated with eachtube m y be adjusted to work simultaneously: to 1m!" rtiallysoastomakcadifierentwave tor-micrthe same sound. Alternatively,one circuit may operate subsequently to the other, by the interaromasposition of a switch in the circuit actuated b! an appropriateelectronic time delay device.

The term of printing mechanism. disclosed dis: grammatically in Figure10 has certain features for use with my invention. A printing drum ll isloosely mounted on a shaft 4!, and is provided with a coil spring l1connected at one of its ends to the hub 48 and at its other end to astationary part, such as a builer 49. An annular ratchet ill is attachedto the drum, so that movement may be imparted thereto by thespringpressed pawl 5| pivoted to the actuating lever 52. A series ofprinting keys lit are mounted around the periphery of the drum. Belowthe drum appropriate means are provided for supporting and actuating,step by step, a printing ribbon 54 and a strip of paper it or theequivalent thereof. A Ti in cia vertically movable, two-positionprinting platen II is disposed beneath the paper. A cam -or lug 81associated with the drum ll is positioned to close contacts 58 when thedrum is at rest and is in the start position, as determined by thebutler it and cooperating stop lug N. In circuit with the contacts 58 isa solenoid it, which will raise the printing platen 58 when energized.The platen has an inclined surtace or wedge 6| which will control theposition of the normally open springpressed contacts 62, in circuit witha magnet pr solenoid ll, which is adapted to shift the position of lever04 to disengage pawl II and locking detent 85 to permit the spring 41 toreturn the drum to start position. impulses-from the circuit 28 or theequivalent are applied to the countor-mechanism by conductors I0, andthrough an appropriate relay Ii and battery 12, actuate the countingmagnet ll. For each impulse thus imparted, to magnet II, the lever 52will move one stroke, and the drum, through the pawl and ratchetmechanism 50, BI will be moved. The printing impulses, either iromconductors it of the circuit of Figure 'l, or from the conductors 29,Figure 6, are applied to the printing solenoid or relay 28 to actuatethe lever ll which depresses the appropriate printing key 53, to printan indicia corresponding to the sound emitted. Depression of theprinting key It results in a downward movement of the wedge BI and aclosing of the contacts 62. Thereupon, themagnet 63 is energized and thelever 84 shifted to position to disengage the pawl BI and detent 85, topermit the drum to return to its original position. Such action closesthe contacts BI and energizes the solenoid 60, whereupon the platen isshifted to its upper position for a subsequent printing operation, andthe lever is shifted to permit the detent and pawl li again to engagethe ratchet. Thus, the parts are in position for the next printingoperation.

It must be understood that any well known type of impulse printer may besubstituted for the novel one disclosed herein.

If it is desired to use an instantaneous volume control in connectionwith thisinvention, a control oi the type shown in United States PatentNo. 1,737,830 is suitable.

I claim:-

I. The method of producing visible intelligible indicia corresponding tointelligible audible sounds, comprising propagating such a sound,projecting a movable beam, causing satd beam to traverse a wave formpath, controlling the form or said path by said sound, providing aplurality of indicators, each adapted to indicate a visible indiciacorresponding to an intelligible audible sound, selecting, by meanscontrolled by said wave form path, the indicator corresponding to thesound utilised to control the form thereof, aminactuating said indicatorto make said indicia visi e.

2. The method of producing a visible intelligible indicia correspondingto intelligible sounds, comprising propagating such a sound, projectinsamovingbeamontoatarget,causingsaidbeam to traverse a wave form path onsaid target corresponding to said sound. providing a plurality ofvisible intelligible indicators, selecting an indicator corresponding tosaid sound by selection efiected by said wave form path on said targettratzersed by said beam, and actuating said indica r.

3. The method of producing visible intelligible corresponding tointelligible audible sounds, comprising providing a target having aplurality of active areas thereon, said areas being arranged inaccordance with a plurality of wave form patterns corresponding topredetermined audible sounds, propagating a sound, projecting a beam andcausing the same to traverse a wave form path on said target,controlling the term of said path by said sound to substantiallycoincide with one of said patterns on said target, and actuating anindicator corresponding to said sound by energy transmitted through theactive areas 0! said pattern.

4. The method of producing visible intelligible indicia corresponding tointelligible audible sounds, comprising providing a target having aplurality of isolated electron transmissive spots thereon arranged inaccordance with a plurality of patterns, propagating an audible sound,projecting a beam of electrons onto said target, causing the same totraverse a wave form path, controlling the form of said path by saidsound. and causing the same to substantially coincide with one oi saidpatterns, and using the beam of electrons encountering said transmissivespots 'on said target to select an indicator correspondin to said sound.

5. The method of producing visible intelligible indicia corresponding topredetermined sounds, comprising propagating such a sound, projecting anelectron beam, causing the beam to traverse a wave form pathcorresponding to said sound. masking said beam during a portion of saidpath, and utilizing the beam during the unmasked portion of the path tocontrol the selection and actuation of a visual indicator correspondingto said sound.

6. The method of producing visible intelligible indicia corresponding topredetermined sounds, comprising propagating such a sound, projecting anelectron beam, causing the beam to traverse a wave form pathcorresponding to said sound, masking said beam during a portion or itstraverse of said path and unmasking it during another portion, providingvisual indicators tor a plurality of predetermined sounds, and selectingthe proper indicator corresponding to said propagated sound by the beamduring the unmasked portion of its traverse of said path.

7. The method of producing visible intelligible indicia corresponding topredetermined sounds, comprising propagating such a sound. projecting anelectron beam, causing the beam to traverse a wave form pathcorresponding to said sound, masking'saidbeamduring aportion of itstraverse oi said path and unmasking it during other interrupted portionsand thereby causing an intermittent projection of said beam beyondthernask,andutilisingthesumoftheprojectime or said beam during theunmasked portions to control the selection of an indicator correspondingto said sound.

8. The method 0! producing visible intelligible indicia corresponding topredetermined sounds. comprising propagating such a sound. projecting anelectron beam. causing the beam to traverse a wave iorm pathcorresponding to said sound. maskingsaidbeamduringaportionoiitstraverseoissidpathandunmaskingitduring other interrupted portions andthereby causing an intermittent projection oi said beam beyond the mask,and utilizing the number or duration or frequency oi the projections oithe beam during the unmasked portions of the path to control theselection of an indicator corresponding to said sound.

indicia corresponding to predetermined sounds. comprising propagatingsuch a sound, projecting an electron beam. causing the beam to traversea wave form path corresponding to said sound. masking said beam duringthe major portion of its traverse of said path and unmasking it at asingle definite point in its path and thereby causing a single isolatedprojection of said beam beyond the mask during its traverse of saidpath. and utilising said projection oi said beam to control theselection of an indicator corresponding to said sound.

10. The method oi producing visible intelligible indicia correspondingto predetermined sounds, comprising propagating such a sound. m lestingan electron beam, causing the beam to traverse a wave form pathcorresponding to said sound masking said beam during the major portionof its traverse of said path and unmasking it at a single definite pointin its path and thereby causing a single isolated projection of saidbeam beyond the mask during its traverse oi said path, and utilizingsaid projection of said beam to illuminate a fluorescent area to makevisible an indicia corresponding to said sound.

11. An apparatus for converting intelligible sounds into visibleintelligible indicia comprising means for producing an undulatingcurrent correspondingtoaparticularsoimdmeanstorprojecting a iocussedbeam 0! electrons, means for causing said beam to traverse a wave formpath corresponding to said undulating current. a plurality of visualindicators corresponding to a plurality oi said sounds, and selectormeans controlled by the beam in its traverse oi said wave form path tocontrol the actuation of one of said indicators corresponding to thesound producing said undulating current.

12. Electron control apparatus comprising, in combination, means [orprojecting a beam of electrons. means ior causing said beam totraverse-a wave form path and (or controlling the contour of said path.an electron absorber positioned to be encountered by said beam. and amask interposed between said source and said electron absorber, saidmask being imperlorate throughout the major portion oi its area and 9.The method oi producing visible intelligible having a plurality oi holestherethrough, said holes being arranged to coincide with a path orpredetermined contour traversed by said beam of electrons under thecontrol of said means. thereby to eilect projection oi said beam throughthe holes in said mask and the contact thereoi upon said absorber.

13. Means for converting speech sounds into visible indicia comprisingmeans for projecting a beam of electrons, means for causing the beam totraverse a diflerent path for each sound, a screen in the field of saidbeam oi electrons, said screen having a plurality of patterns oiperiarations thereon. each pattern coinciding with a particular path. aplurality of indicators and means sotuated by the projection of saidelectron beam through said screen to select an indicator correspondingto the pattern traversed by said beam and to the corresponding sound.

it. An apparatus ior converting sounds into visible indicia comprising amicrophone. means for filtering and amplifying voice currents controlledby said microphone, a cathode ray tube, circuits for controlling theprojection oi the electron beam therein as to amplitude and time, aperforated screen associated with said tube. a charge selectorpositioned behind the screen. and a printing device adapted to becontrolled by said charge selector.

\ WALLACE WA'I'I J. FUHER.

CERTIFIOAIE 01" CORRECTION.

rasent lio u 2.157.888 e llovnaber 22, 1938 It is hereby certified thatthe name or the patenteelin the above mmbored patent was erroneouslyIrittenandprintedas "Wallace Hatt I mler" whereas said name should havebeen written and printedaswailaoe H. Fuller, as shown bythe records oithis office; andthat the said letters Patent shouldbe read with thiscorrection therein thatthe same may eonrorn to the record oi' the easein the Pateht Office.

. signed and sealed this ll th day or February, MD. 1939.

(Seal) Henry Van Arsdale Acting Cosmissioner of Patents.

